Biol 1300 Unit 4.docx

**Biol 1300 Unit 4** **FRUIT AND NUTS** Botanically, a fruit is the mature, ripened ovary of a flowering plant, containing seeds. This definition includes a wide variety of structures, such as cereal grains, legumes (e.g. pea pods, beans), nuts (e.g. hazelnut), and berries (e.g. tomato, squash), w...

**Biol 1300 Unit 4** **FRUIT AND NUTS** Botanically, a fruit is the mature, ripened ovary of a flowering plant, containing seeds. This definition includes a wide variety of structures, such as cereal grains, legumes (e.g. pea pods, beans), nuts (e.g. hazelnut), and berries (e.g. tomato, squash), which differ from the common grocery store definition that only includes fleshy, sweet fruits like oranges and apples and sweet non-floral parts like rhubarb. The seeds develop from fertilized ovules within the ovary (ovules in plants are the equivalent of eggs in animals), and as the fruit matures, the ovary wall becomes the pericarp, which encloses the seeds. The pericarp can have three layers: exocarp (outer), mesocarp (middle), and endocarp (inner). [Most flowers contain both male and female parts](https://earthsky.org/earth/do-flowering-plants-have-sexes/). [The male parts, called stamen, produce pollen, while the female parts, called carpels or pistils, contain the ovary](https://sciencing.com/parts-flowers-do-8173112.html). [This allows for efficient pollination, often by insects, birds, or other pollinators](https://earthsky.org/earth/do-flowering-plants-have-sexes/). The seeds develop from fertilized ovules. Flowering plant fruits are classified according to: 1. whether they develop from a flower with a superior or inferior ovary -Superior: the ovary is on top of flower -Inferior: the ovary is under the flower 2. whether the fruit is dry or fleshy at maturity -Fleshy: watery & juicy (e.g., apple, oranges) -Dry: not watery (e.g., nuts, grains) 3. whether the fruit is simple (derived from a single ovary on a single flower), aggregate (derived from the fusion of multiple ovaries on a single flower, note that aggregate means a combination of separate parts), or multiple (multiple ovaries and multiple flowers). The simple type is most common. **ROSE (ROSACEAE) FAMILY** This is a very large eudicot family of mostly temperate species. Most members of the Rose Family have showy, insect-pollinated flowers that are produced in the spring. Rose fruits are often fleshy, large and showy, and in nature many are dispersed by animals. This plant family is very important economically, and numerous species are grown commercially in temperate regions of the world. The Rose Family consists of four subfamilies, three of which are of considerable economic importance as foods: **SUBFAMILY ROSOIDAE** Economically important members of this subfamily include the raspberry (Rubus idaeus), blackberry (R. fruticosus) and strawberry (Fragaria ananassa). All produce an aggregate fruit (associated with the floral receptacle, tissues near the end of reproductive stems that are situated below or encase the reproductive organs) that is not a true berry (in the botanical sense, berries have a single fruit for every flower). Two aggregate fruit types are distinguished: genus Rubus (raspberry, blackberry): the receptacle stays behind when picked, so that the portion eaten appears \"hollow\". Botanically, these are aggregate fruits consisting of many loosely attached small drupelets; each seed is encased in a sweet pulp. genus Fragaria (strawberry): the receptacle, which turns fleshy and sweet, is also eaten. Botanically, this is an aggregate fruit consisting of numerous tiny achenes or nutlets (colloquially strawberry \"seeds\", but actually tiny nut-like simple fruits) attached to reddish, fleshy receptacle tissue. **SUBFAMILY PRUNOIDAE** The economically important species of this subfamily are all members of the genus Prunus; they include the plum (P. domestica), peach and nectarine (P. persica), apricot (P. armeniaca), cherry (P. avium) and almond (P. dulcis). Most of these species are native to Eastern and Central Asia. The prunoids produce a \"stone\" fruit known as a drupe, which develops from an ovary with a single ovule; thus, there is a single seed per fruit. Generally, the exocarp (the \"skin\" of the fruit) and mesocarp (the sweet fleshy portion) are eaten, while the \"stone\" (the woody endocarp, which encloses the seed) is thrown away. A notable exception is the almond, which is a roasted seed (the inedible pericarp is woody and bitter tasting). **SUBFAMILY MALOIDAE** Economically important members of this family include apple (Malus domestica), pear (Pyrus communis) and quince (Cydonia oblonga). Members of this subfamily produce a unique fruit known as a pome, which develops from an inferior ovary. The sweet portion that is eaten arises from non-floral hypanthium (receptacle) tissue, which enlarges to envelop the maturing inferior ovary. The pericarp (the portion of the fruit derived from the ovary wall) is the inedible \"core\" containing the seeds. Most apple and pear varieties derived from species native to Eastern and Central Asia, although some pear varieties are thought to be native to Europe. The most economically important member of this subfamily is the apple. All apple varieties (there are hundreds) are derived from the same species, *Malus domestica*. The fruit develops from a five-parted inferior ovary. Older apple varieties are diploid and produce viable seeds, but most modern cultivars are triploid and therefore sterile (since the chromosomes cannot pair at meiosis). Triploid cultivars are propagated vegetatively, usually by grafting. **TOMATO (SOLANACEAE) FAMILY** This is a large eudicot family of worldwide distribution. Members of the Tomato Family were particularly important to agricultural development in South and Central America. In addition to its importance as a source of food fruits, the family also includes other domesticated species such as tobacco, potato, and several medicinal, drug and poisonous plants. Botanically, the fruits of this family are true berries. Important edible solanaceous fruits (remember the botanical definition) include: **TOMATO** (Lycopersicon esculentum): The tomato is native to Central America and was first domesticated by the Mayans. The tomato was not initially accepted in parts of Europe, since most European species of the Tomato Family are poisonous (e.g. henbane, deadly nightshade and belladonna). Indeed, the tomato was once known as the \"devil\'s food\" in southern Europe. The wild progenitor of the modern cultivated tomato was small (similar in size to a cherry tomato) and much more pungent than modern cultivars. Recent plant breeding programs have tended to emphasize size and keeping qualities, often at the expense of flavour. **SWEET AND CAPSICUM PEPPERS**: Sweet and hot capsicum peppers (*Capsicum annuum* and *C. frutescens*) originated in Central America. They are mostly hybrids from closely related species within the genus *Capsicum*. There are many cultivars with varying sizes and levels of "hotness," which is due to capsaicin concentrated in the fruit's placental tissue. Peppers are widely used in global cuisines, including Hungarian, Italian, Spanish, Chinese, Indonesian, Southeast Asian, African, and Central and South American cooking. It is hypothesized that pungent spices like capsicum pepper were initially used to mask the smell and taste of unrefrigerated meats and other foods. **EGGPLANT or AUBERGINE** (Solanum melongena): The egglant originated in India, where it remains an important dietary item. There is considerable variation in the size, shape and colour of eggplant fruit, with colour ranging from pure white to deep purple. While not particularly popular in North America, eggplant is used commonly in India and parts of Europe (e.g. Greek mousaka). The flesh of the fruit is generally fried or baked. **PUMPKIN (CUCURBITACEAE) FAMILY** Members of this large eudicot family, commonly known as the pumpkin family, are found worldwide, especially in tropical and subtropical regions. Most are vines with separate male and female flowers (may be on the same or different plants). The female flower's inferior ovary develops into a pepo, a modified berry-type fruit. This family is highly mutable and was significant in agricultural development in both the Old (Europe, Africa, Asia) and New Worlds (Americas). The fruit flesh and seeds are important food sources, and early civilizations used dried and hollowed fruits for water storage and as drinking vessels. Important food crops in this family include the following genera: genus Cucurbita: members include pumpkin (C. maxima), butternut squash (C. moschata), gourd (C. ficifolia), and zucchini or summer squash (C. pepo). All are native to the Americas (Mexico and/or Peru). genus Cucumis: important commercial crops are melons (C. melo) and cucumber (C. sativus). Both are native to Africa. genus Citrullus: watermelon (C. lanatus) belongs to this genus; it is native to the deserts of south-west Africa. Several other species are important in tropical areas; these include the single-seeded chayote (Sechium edule) used in Caribbean and Malaysian cooking, the luffa gourd (Luffa acutangula) used to produce a natural scrub-brush, and the bottle gourd (Lagenaria siceraria) used to produce drinking vessels. **HEATH (ERICACEAE) FAMILY** The Heath Family (Ericaceae) is a large eudicot family found worldwide, especially in north temperate regions. Most species are woody shrubs that thrive in acidic soils and rely on fungal mycorrhizal associations. Their leaves are often evergreen, thick, and waxy. This family includes many important ornamental shrubs like rhododendrons, heathers, and heaths. The genus Vaccinium includes several significant edible berries such as blueberry (V. corymbosum), bilberry (V. myrtillus), lingonberry or patridgeberry (V. vitisidaea), and cranberry (V. macrocarpon). Blueberries are cultivated in the northern United States and both eastern Canada (Maritimes, Quebec, and Ontario) and coastal British Columbia. Bilberries are like blueberries, but are usually darker, rounder, and smaller. Cranberry bogs are found in the eastern United States, Oregon, Washington, and British Columbia. **CITRUS (RUTACEAE) FAMILY** This eudicot family is mostly restricted to tropical and subtropical regions; few members of the family are frost tolerant. Most produce large, showy and fragrant insect-pollinated flowers. The economically important fruit-producing species belong to the genus Citrus, and all produce a large, modified berry known as hesperidium, which means it has leathery outer skin (the exocarp and mesocarp) surrounding the pulp or juice sacs (endocarp). Citrus fruits include important species like lemon (C. limon), lime (C. aurantiifolia), orange (C. sinensis), mandarin or tangerine orange (C. reticulata), grapefruit (C. paradisi), and pomelo or shaddock (C. maxima). Other locally used species are kumquat (Fortunella margarita), Seville or sour orange (C. aurantium), and makrut lime (C. hystrix). Citrus fruits produce aromatic oils for cosmetics, perfumes, and food additives. They are a vital source of vitamin C, preventing scurvy, a condition causing skin blotches, gum deterioration, and mucous membrane bleeding. In 1753, it was discovered by Dr. James Lind that scurvy could be treated with citrus fruits, leading British naval vessels to carry lemons or limes, earning British sailors the nickname "limeys." **SOAPBERRY (SAPINDACEAE) FAMILY** This eudicot family includes several Asiatic fruits such as longan (Dimocarpus longan), litchi or lychee (Litchi chinensis), and rambutan (Nephelium lappaceum). The akee (Blighia sapida), native to tropical West Africa, is widely grown in Jamaica and other Caribbean countries. Jamaica's national dish, "akee and saltfish," features salted cod sautéed with boiled akee, onions, peppers, tomatoes, and herbs. Most of the akee fruit is dangerously poisonous, with only the fleshy arils around the seeds being edible if the fruit is fresh and has opened naturally. Consuming immature or over-ripe akee arils can cause "Jamaican vomiting sickness," characterized by severe vomiting and hypoglycemia (deficiency of glucose in the blood). Guarana (Paullinia cupana) is a species from the Amazonian region of South America. Its fruit contains significant amounts of caffeine and is used to make a popular South American caffeinated beverage. Guarana is also a key ingredient in energy drinks sold in Europe and North America. **MULBERRY (MORACEAE) FAMILY** Economically important members of this family produce multiple fruits. White and black mulberries are minor temperate crops (Morus alba and M. nigra, respectively). Figs (Ficus carica), produced by a large subtropical tree, are commercially significant. Breadfruit and jackfruit, rarely seen in North America and Europe, are important carbohydrate sources in the tropics and produce large greenish fruits. Breadfruit is starchy and must be cooked before eating. Captain Bligh was transporting breadfruit seedlings during the famous *Mutiny on the Bounty fame*, discouraging further exportation. Jackfruit's sweet fleshy segments have a pineapple-melon flavor and are eaten fresh or canned. **OTHER TEMPERATE FRUITS** **GRAPE** (Vitis vinifera): The wine grape is a large perennial woody vine native to the Eastern Mediterranean region. While some grapes are grown commercially to be eaten fresh (or dried to form raisins), the vast majority are used to produce wine. Commercial winemaking is discussed in a later section. **POMEGRANATE** (Punica grantum): The pomegranate is a small tree native to the Middle East (Southwest Asia). It is a multi-seeded fruit; each seed is surrounded by a bright red pulp known as the aril. This pulp is juiced to produce the beverage grenadine. **KIWI** (Actinidia deliciosa): Although indigenous to China, the kiwi or Chinese gooseberry was first commercialized in New Zealand, where it remains an important export crop. This vine species is also grown in California. **OLIVE** (Olea europea): The olive is a large, long-lived tree native to the Mediterranean region. The fruit is an important source of cooking oil (discussed in a later section). Olives may also be processed as a food; the fruit must be treated with a caustic soda (sodium hydroxide) to remove a bitter chemical alkaloid. Following this treatment, the fruit is either dried or pickled. **OTHER TROPICAL FRUITS** Many subtropical and tropical plant species produce fruit that are wild-harvested or grown commercially on a small scale. While some can be found in North American supermarkets, others do not transport easily and are consumed only locally (e.g., sensitive to colder temperatures). Examples include: -**Passion fruit**: native to Brazil -**Guava**: common in Central America and Asia -**Cherimoya**: native to Peru, Ecuador, and Colombia -**Starfruit**: native to Southeast Asia -**Dragonfruit**: native to Southern Mexico -**Mangosteen**: a tropical evergreen tree with edible fruit native to Island Southeast Asia **COMMERCIALLY IMPORTANT MONOCOT FRUIT** Important and commonly available tropical fruits include: **PINEAPPLE** (Ananas comosus): The pineapple is a monocot species native to the Americas. It produces a large multiple fruit derived from the fusion of 100-200 separate fruits, each from a single flower. It is grown commercially as a dessert fruit, and to produce a natural protein-degrading enzyme. Pineapple leaves are also a source of coarse plant fiber used to manufacture mats and sacks. **BANANA** (Musa acuminata): Bananas, native to Eastern Asia and northern Australia, are monocot species cultivated in various forms, including sweet dessert types and starchy plantains. These sterile triploid plants are propagated from stem cuttings and hence produce seedless fruit. Female flowers form large inflorescences, allowing bunch harvesting. To prevent spoilage, bananas are harvested unripe, transported at cool temperatures, and artificially ripened with ethylene gas. The United Fruit Company popularized bananas in North America, controlling Central American economies and politics, leading to the problematic term "banana republics" for producer countries like Nicaragua and Costa Rica. Bananas are vulnerable to black sigatoka fungus on mostly their leaves, which can affect yield by 50% or more. **DATE PALM** (Phoenix dactylifera): This tree-like monocot palm is thought to be indigenous to the Near East (Mesopotamian valley, Southwest Asia). The date fruit is rich in vitamins and contains 75% carbohydrates (mainly sugars) and 25% protein. **COCONUT** (Cocos nucifera): The coconut, a large monocot palm native to South Pacific Islands (Philippines, Malaysia New Guinea), produces one of the world's largest seeds. The hard endosperm, known as coconut "meat" or copra, was a vital energy source for South Sea islanders. Today, copra is used to produce coconut oil, a common ingredient in chocolate and candies, and as a food flavoring and dessert. The liquid portion, known as coconut milk, is also endosperm tissue. The coconut is highly versatile, historically providing clothing, building materials, and drinking vessels for early South Sea islanders. **COMMERCIALLY IMPORTANT DICOTS** **DURIAN** (Durio zibethinus): The durian is a tall eudicot tree native to western Malaysia (Southeast Asia). It produces a very large (up to 5 kg) prickly fruit that is very popular in Southeast Asia. The portion eaten is the fleshy pulp (arils) that surround the seeds. This fruit is known for its highly pungent sulphurous aroma, complex taste (an odd mixture of bananas, caramel, vanilla and garlic) and creamy texture. **AVOCADO** (Persea americana): The avocado is a large magnoliid tree indigenous to Central America. The mesocarp of the avocado fruit is rich in oil (like olive oil), an unusual feature in flowering plants. Avocados are very nutritious: they are high in calories and a good source of vitamins A and C, niacin and riboflavin. Guacamole, of Aztec origin, is mashed avocado paste mixed with various spices. **MANGO** (Mangifera indica): The mango, a large tropical tree native to India and Malaysia (Southeast Asia), has been cultivated for at least 4,000 years. The ripened fruit is widely available in North American supermarkets as a sweet dessert fruit. Unripe mango fruit, which has a sharp acidic taste, is widely used in Asian and Indian cooking (e.g. mango chutney). Mango belongs to the same family as the cashew and pistachio. **PAPAYA** (Carica papaya): The papaya is a small tropical tree indigenous to Central America. The large, yellow fruit is popular in many tropical countries. It is now commonly available in European and North American supermarkets. **NUTS** Botanically, the term nut only applies to dry, one-seeded indehiscent fruits with a hard, woody pericarp (e.g. hazelnut, Corylus avellana). More commonly, the term is used to describe edible, high-protein mealy seeds obtained from certain plant species. Important temperate nuts (using the common definition of the term) include: **WALNUT** (Juglans regia): The walnut is a large tree indigenous to Southeast Europe and Western Asia (a related North America species, J. nigra, is also used). The species produces a bitter-tasting, drupe-like fruit. The ripe fruits are harvested and processed by removing the exocarp and mesocarp: the \"nut\" sold commercially consists of the woody endocarp (the \"shell\" of the walnut) which is cracked open to extract the mealy edible seed. The seeds can also be processed into a high-quality cooking oil. **PECAN** (Carya illinoinensis): The pecan is a large tree indigenous to the southern United States and adjacent Mexico; it belongs to the same family as the walnut. The fruit splits open at maturity to reveal the \"nut\", which (like the walnut) is the woody endocarp containing a single edible seed. **ALMOND** (Prunus dulcis): The almond, a small tree native to Western Asia, is a member of the Rose family. Like other commercially important species of the genus Prunus (e.g. cherry, peach, plum), the fruit is a single-seeded drupe. The bitter, inedible mesocarp of the almond fruit is removed during processing. Almonds are often marketed with the \"shell\" (endocarp), which is cracked open to extract the edible seed. This is the only member of the Rose family where the seed is edible. **HAZELNUT** (Corylus avellana): The hazelnut is a tall shrub native to Eurasia. The ripe fruit, a woody indehiscent pericarp which has a single seed, is botanically a \"true\" nut (botanical definition). Several tropical plant species also produce edible seeds or \"nuts\": **CASHEW** (Anacardium occidentale): The cashew is a large evergreen tree native to northeast Brazil. The seeds are roasted to remove irritant oil. The swollen fruit stalks, known as \"cashew apples\", are used locally to produce jams, candied fruit, and a popular Brazilian drink known as cajuado. Thus, both the cashew fruit (cashew apple) and the seeds (cashew nuts) are edible. **PISTACHIO** (Pistacia vera): The pistachio, a small tree indigenous to central Asia, is related to the cashew (both part of cashew family). It produces a fleshy drupe-like fruit with a woody endocarp (the \"shell\") that splits open when dry to reveal a single edible, greenish seed. **BRAZIL NUT** (Bertholletia excelsa): The brazil nut is an enormous tree (up to 40 m high) native to Amazonian rain forest (South America). The wild-harvested nuts (gathered after they fall to the ground) are an important source of income for indigenous peoples of the Amazon basin. The fruit, a large (to 2.5 kg) woody capsule that takes 15 months to mature, contains an endocarp with 10-25 large edible seeds. In recent years some commercial Brazil nut plantations have been established. **MACADAMIA NUT** (Macadamia integrifolia): The macadamia tree is native to south-east Australia. It was introduced to Hawaii in 1930, where it became an important commercial crop. The round, green-coloured fruit splits at maturity to reveal a thick shell (the endocarp) containing a single, white, waxy edible seed. Some consider the macadamia to be the tastiest of all gourmet nuts. They are highly toxic to dogs.